Null model — where it appears
Named by 2 essays across 2 fields — each of them below, with the objects they name alongside it.
Fitting the exponent
Assuming the exponent is three and reporting the error tells you how wrong the data is. Fitting the exponent and reporting what it comes out as tells you what the network is doing — and the machinery has to be shown returning something other than three, or it is not a fit.
The second moment is the measurement
The mean number of sides in a cellular tissue is six, and Euler's formula leaves it no choice — so it takes the same value on a golden-angle head, a whorled head and a set of random points. The mean squared departure from six varies by a factor of eighty across the same three, and almost nobody reports it.
Named alongside it
The objects these essays reach for when they reach for this one.
Aboav–WeaireBranchCell areaCylinderDa Vinci's ruleDiscriminationDisorderEuler's formulaExponent fittingFibonacciGolden angleL-systems